Existing vehicles include autonomous driving technologies (e.g., automatic parking programs or automatic steering programs) that depend on accurate vehicle dimensions. For example, autonomous parking programs rely on length and width of the vehicle when determining whether a potential spot can accommodate the vehicle. One solution is to preprogram vehicle dimensions at the time of manufacturing. Customers, however, may affix objects to the vehicles (e.g., bicycle racks) that alter the dimensions and render the programmed dimensions inaccurate. A new solution is needed to accurately and automatically determine updated dimensions of vehicles.